Juha Sarkkula

Learn More
Rapid development in the upper reaches of the Mekong River, in the form of construction of large hydropower dams and reservoirs, large irrigation schemes, and rapid urban development, is putting water resources under stress. Recent studies have concluded that these developments will lead to flow alterations in the Mekong River. These flow alterations would(More)
INTRODUCTION The Tonle Sap Lake and floodplains in the heart of Cambodia contain the largest continuous areas of natural wetlands habitats remaining in the Mekong system, while being the largest permanent freshwater body in Southeast Asia (Figure 1). Tonle Sap is a crucially important source for food and living in Cambodia. More than one million people live(More)
The Tonle Sap Lake in Cambodia is a dynamic flood-pulsed ecosystem that annually increases its surface area from roughly 2,500 km(2) to over 12,500 km(2) driven by seasonal flooding from the Mekong River. This flooding is thought to structure many of the critical ecological processes, including aquatic primary and secondary productivity. The lake also has a(More)
The effects of nutrient load reductions on the biomass of N-fixing cyanobacteria were evaluated in the scale of the Gulf of Finland. The two analysed reduction scenarios were Finnish national agenda and the improvement of phosphorus removal in the present purification plants of St. Petersburg. The effects of load reduction scenarios were tested by using a(More)
It has been claimed that Tonle Sap Lake is rapidly filling with sediment as a result of increasing sediment yields from the catchment. Infilling of the lake basin would have serious implications for the magnitude of flooding in central Cambodia and the Mekong Delta region and threaten the lake's unique ecosystem. In this article, we synthesize the results(More)
[1] Hydraulic erosion of bank toe materials is the dominant factor controlling the long‐term rate of riverbank retreat. In principle, hydraulic bank erosion can be quantified using an excess shear stress model, but difficulties in estimating input parameters seriously inhibit the predictive accuracy of this approach. Herein a combination of analytical(More)
The sewage water of the city of Vaasa, located at the Gulf of Bothnia, pollutes the surrounding coastal areas and beaches near the city. The sewage outlet is planned to be moved to some other place in order to decrease the harmful effects in the most valuable areas close to the city. The currents and transport processes in the area were examined in order to(More)
a) Water Resources Laboratory, Helsinki University of Technology, 02015 HUT, Finland (emails: olli.varis@hut.fi, matti.kummu@iki.fi, keskinen@iki.fi, ulla.heinonen@hut.fi, katri.makkonen@hut.fi) b) Finnish Environment Institute (SYKE), Mechelininkatu 34a, 00251 Helsinki, Finland (email: juha.sarkkula@environment.fi) c) Environmental Impact Assessment Centre(More)
  • 1